Late, fast spring runoff
changes drought dynamic
By MATT FURBER
Express Staff Writer
Warm temperatures at the end
of May washed hopes of drought improvement out of the Wood River Valley, but the
quick runoff will feed more of the vast agricultural demand to the south.
"We gained about three
weeks of irrigation time," said Big Wood Canal Company manager Lynn Harmon,
speaking about the water levels at Magic Reservoir, which is the main collector
of Big Wood water. "The faster it comes off, the more we receive."
As it happened, this year’s
snowmelt had less time to seep into the water table or be gathered in collection
ponds. As earlier concerns about another drought year are being reconfirmed, the
dynamics of drought conditions in the region are changing somewhat.
In April, Harmon told the
Mountain Express he expected about 35 to 45 days of water this summer. But
"the whole southern part of the state has seen improvement," said
Harmon. "We should see total irrigation water at Magic at 70 days."
That capacity is close to
half the volume necessary to count as a normal season, which is 150 days.
Drought concerns were never
far away this season. Gov. Dirk Kempthorne signed a drought emergency
declaration for Blaine County four days before the Big Wood River crested May
The declaration allows
irrigators to expedite changes in the direction of their water plan for the
season, although it doesn’t permit them to increase their intake of water.
So far only one application
from the Carey area is expected at the Idaho Department of Water Resources
office in Twin Falls. As the irrigation season progresses, however, the state
will probably see more applicants, said Harmon.
Suggesting concerns about
water quality, IDWR also announced May 22 that groundwater levels show declines
and cautioned that aesthetic pond owners "may be in violation of state
water law if they do not have an approved water right that authorizes the
impoundment of water."
As counter-intuitive as it
seems even for legal irrigators with surface or ground water rights, the
overflow of the Big Wood River spells more water trouble.
"Anytime you impound
water you will see evaporation," said Harmon.
But the bigger concern is the
impact of pond water that is too warm or contaminated seeping back into the
water table or draining to the river.
Residential water users with
rights in the county are permitted by state law to irrigate only a half acre of
land with as much as 13,000 gallons per day.
"If you have (water)
rights you can choose to exercise them in any way you want," said Alpine
Aquatics water manager, Kevin Lenane, who is managing an automated waterfall
project in Deer Creek. "I recommend that people ‘pond’ responsibly.
That water is like money the state is giving away."
"There is an important
vegetative component to the greenway," he added. "If people remove
cottonwoods, allow fertilizers, sediments and nutrients to drain into the river,
degradation is going to occur. "
Ideally, following peak
accumulation, snow in the mountains will dribble gradually out of the snow pack,
said Natural Resource Conservation Service water supply specialist Ron
Abramovich. "But, when the temperature in the mountains starts pushing 80
(degrees Fahrenheit), it will go down almost as quick as it came in. (When
Mother Nature) gives you extremes, streams respond accordingly."
"If the water had run
off more slowly (as expected), we may have seen 25 percent of what we
received," said Harmon. "In the next four or five days we will see the
end of the peak runoff for the season, but we will still get some water from
natural spring flows."
Since all water rights are
managed by a priority date the most senior right holders (those with the oldest
rights) get water first.
"Some late rights
(irrigators) will stay on a little longer," said Harmon. But, he adds there
have already been cuts like 1894 rights in the Little Wood River drainage that
feeds Richfield and joins the Big Wood River below Magic Reservoir.
"Water rights in Idaho
are not designed to be nice," said Idaho Department of Water Resources
spokesman Dick Larsen. "Water rights dependant industries like fish
hatcheries or bottle water companies know the oldest rights are a